Current-regulator foe incandescent lamps



R. T. CHEESEMAN.

CURRENT REGULATOR FOR INCANDESCENT LAMPS.

APPLICATIQN FILED DEC-14. I911.

Patented Dc. 30, 1919.

His Attorney.

UNITED snare RALPH T. CHEESEMAN', F LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CURRENT-REGULATOR FOR INCANDESCENT LAMPS.

Specification of Letters Patent.

Patented Dec. 30, 1919.

Application filed December 14, 1917. Serial No. 207,104.

' To all whom z'tmay concern."

Be it known that I, RALPH T. OHEESEMAN,

. Incandescent Lamps, of which the following lamp is allowed to exceed that desired for normal operation the life of the lamp will be greatly shortened.

One of the objects of my invention is to provide a simple an convenient means for regulating the current in the lamp which can quickly be adjusted by the operator for preventing the current from exceeding the safe operating value.

To accomplish this object, when the lamp is operated by alternating current, I employ an adjustable impedance in the supply c rcuit and provide a current measuring 1nstrument in the lamp circuit. The operator may quickly tell by reading the measuring instrument when the current in the lamp varies from normal and vary the impedance to adjust it to the desired value.

If the lamp should be turned ofi with the impedance adjusted to its minimum value the current in the lamp, when started again,

might exceed the safe operating value and j mg, as indlcated 1n Fig. 1.

the life of the lamp would be accordingly shortened. a

A second objectof my invention 1 to overcome this disadvantage and provide an arrangement in which it will be impossible for the operator to start the lamp unless the impedance is ad'usted to its maxnnum value. In attaining this object I provide a switch in the supply circuit and place this switch in such relation to the means for adjusting the impedance that the switch can be operated to close the circuit only when the impedance is adjusted to its maximum value.

My invention will best be understood by reference to the following description taken in connection With theaccompanying drawing, in which Figure 1 is a view of a casing which contains the regulating apparatus showing the means by which the operator controls the lamp, and Fig. 2 is a view, partly in perspective and partly diagrammatic, showing the relation between the different parts of the apparatus and the supply circuit connections.

As indicated in the drawing, the lamp 1 is supplied with current from the means 2 through an auto transformer 3 which is designed to furnish the proper operating voltage for the lamp. In series with the primary circuit of the transformer 3 I provide an adjustable impedance comprising an inductive winding 4 and a movable magnetic core 5 within the winding. The position of the core 5 with respect to the winding l and the value of the impedance may be varied by turning the handle 6 which is fastened to the shaft 7, the core being operatively connected to this shaft by means of the strap 8 which passes over and is attached to the drum 9 which is also fastened to shaft 7 In order to hold the core in the desired position, a friction band 10 is employed surrounding the drum 11 which is mounted on the shaft 7 The lamp may be turned on and off by means of a switch 12 in the primary circuit, which switch may be, as indicated, of the ordinary double push button and minimum impedance it will cover the I do not mum.

push button 14 and the operator will be unable to 0 crate the switclr- It will be impossible or him to turn the out first turning the handle 6 to the point of maximum impedance as the handle is so positioned as to prevent the push button 14 from projecting beyond the casing, except when it is opposite the notch 16. When the lamp is turned off the push button 14 projects into the opening in th prevents the handle from being turned until the switch is closed. Thus there 1s no possibility of the operator starting the lamp except when the impedance is at a maxi- The ammeter 17 which is connected in the lamp circuit and mounted on the front of the casing 13 enables the operator to tell at any moment whether the lamp is receiving the proper amount of current.

While I have described and illustrated the preferred embodiment of my inventlon, wish to be limited to the. precise structure and circuit arrangement shown as it will be apparent that many modifications therein may be made without departing from the scope of my invention as set forth in the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States,1s

1. The combination in an apparatus of the class described of anelectr1c c1rcu1t, a switch for closing said circuit having means for the manual operation thereof and means for varying the impedance of said circuit, said means for the manual operation of the switch being so located with respect to sa1d impedance varying means that it can be operated only when the impedance 1s a maximum.

2. The combination in an apparatus of the class described of an'electric circuit supplied by asource of alternating current, a switch for closing said circuit having means -for the manual operation thereof, a react- 4a:-

ance in said circuit and means for varymg Y the value of said reactance, said means for the manual operation of the switch'being so located with. respect to said reactance varysag means that it can be operated only when the reactance 1s a maxlmum.

3. The combination in an apparatus of the class described of an electric circuit supplied by a source of alternating current, a switch for closing said circuit having means for the manual 0 eration thereof, a reactive winding include in said, circuit, a movable core within saidwinding for varying the reactance thereof and means for moving said core to adjust the reactance to" a desired. value, said means for the manual operation of the to the means for moving said core that it can be operated only when the reactance is a maximum.

4., The combination in an apparatus of the lamp ofi with.

e handle andthe class described of an electric cuit, a variable reactance switch being-so located with respectmoving said coreto adjust the reactance to l a deslred value, sa1d means for the manual operation of the switch being so located with respect to said handle that it can be operated onl when the handle is in a predetermined desired position.

5. The combination in an apparatus of circuit supplied by a source of alternating current, a push button switch for closing saidcirincluded in said circuit, and a'handle for adjusting the value of said reactance, said push button being so located with respect to said handle that it can be operated only when the handle is in a predetermined desired position.

6. The combination in an apparatus of the class described of an electric circuit supplied by a source of alternating current, a push button switch for closing said circuit, a variable reactance for adjusting the current in said circuit, and a handle for adjusting the value of said reactance having an opening therein, said push button being so located with respect to said handle that when the reactance is adjusted to any value less than a maximum it will be covered by the handle, and when the reactance is a maximum it will be opposite the opening in the handle.

7. The combination in an apparatus of the class described of an incandescent lamp, a transformer for supplying current, to sa1d lamp, a variable reactive winding for adjusting the current supplied to the lamp, a 7

current supplied to the lamp, said means for the manual operation of said switch being so located with respect to the reactance varymg means that it can be operated only when the reactance is a maximum.

8. The combination in an a paratus of the class described of an incan escent lamp, a transformer for supplying current to said lamp, a variable reactance for adjusting the current supplied to the lamp, a push button switch for closing a circuit to supply current to the lamp, and a handle for adjusting the value of said reactance, said push button being so located with respect to said handle that it can be operated only when the reactance 1s a maximum,

9, The combination in an apparatus of the class described of an incandescent lam a transformer for supplying current to sa1d lamp a variable reactance in the primary circuit of said transformer, a push button switch for closing the prlmary circuit 0T said transformer to supply current to said lamp, and a handle ,for adjusting the value of said reactance having an opening therein, said push button being so located with respect to said handle that when the react anc'e is adjusted to any value less than a maximum it will be covered by the handle, 10 and when the reactance is 'a maximum it will be opposite the opening in the handle.

In Witness whereof, I have hereunto set hand this 12th day of December, 1917.

RALPH T. GHEE SEMAN. 

